Stethoscope



(No Model.,- W. F. FORD.

' STBTHOSGOPE. I No. 257,487 Patented May 9,1882.

f, near its periphery.

UNITED STATES PATENT Orrrce.

WILLIAM F. FORD, OF NEW YORK, N. Y.

STETHOSCOPE.

SPECIFICATION forming part of Letters Patent No. 257,487, dated May 9,1882.

Application filed April 4, 1882.

(No model.)

To all. whom it may concern:

Be it known that I, WILLIAM F. Form, residing at NewYork, in the countyof New York and State ofNew York, have invented certain new and usefulImprovements in Stethoscopes, ofwhich the following is a specification,refer ence being had therein to the accompanying drawings.

My invention relates to a spring connecting the two arms or ear-tubes ofa stethoscope and governing the pressure exerted by the ear-tips in theears of the examiner.

Heretofore the governing-spring has been made of an elastic or spiralwire spring passing between the ear-tubes above and across thehinge-joint. The breath of the examiner causing a vibration of theelastic or spi *a-l wire has given rise to false sounds, which,transmitted by means of the tubes to the ears of the examiner andmingling with the sounds emanating from the chest of the patient, causeda confusion otsounds, which detracted from the value of the instrumentas a means of diagnosis. To obviate this difficulty is the object of myinvention; and to this end theinvention consists in a coiled springinclosed in a casing made in two parts, each part being carried by anarm extendingt'rom one of the tubes, whereby a concealed and noiselessspring is obtained.

In the accompanying drawings, Figure 1 is a. view of an instrument knownas Oannnans stethoscope. Figs. 2, 3, 4, and 5 are detail views.

A is the nozzle which is placed against the chest of the patient, and BB the tubes extending therefrom to the ears of the examiner.

From each tube an arm, (I, extends inward toward the other tube andslightly inclined toward the nozzle. At the end of each arm is acircular shallow box,1'), somewhat resembling one-half of a case forinclosing a watch-spring. One box is provided with a central fixed post,6, and the other box is provided with a stud, One end of a coiledspring, G, is attached to the post 6, and the other end is attached tothe stud f. The two boxes are placed together to form a close casl l l ling, and are secured by a nut, H, fitting on the screw-threaded end ofthe post 0, which projects through a central hole in its opposite box ina similar manner to that adopted for securing the case of a pocketmeasuring-line; or, in lieu thereof, a screw,K, maybe passed through thepost and engaged with the nut, as shown in Fig. 4.

On the periphery of each box B are two shoulders, I m, located less thanone hundred and eighty degrees apart, so as to allow an axial play of afew degrees, but to limit said play.

he operation is as follows: When the instrument is not in use the twoshoulders H are together. When it is to be used the tubes '3 B are movedoutward suliiciently to allow their ends to be inserted in the cars ofthe ex aminer, during which motion the arms 0 (J move upward toward asti aight line with each other a number of degrees equal to the numberof degrees traversed by the tubes and until arrested by the shoulders mm coming together. The ends of the tubes are then placed in the ears,and the tendency of the spring (I to expand pulls the tubes toward eachothe and holds them in place with sutiicient pressure. to cause theirends to lit closely in the ears of the examiner.

\Vhat I claim as new, Letters Patent, is-

l. The combination, with a stethoscope, of a concealed noiseless springinclosed in a easing made in two parts and connected with the tubes ofthe instrument, substantially as and for the purpose herein described.

2. The combination, with the tubes B B,-of the arms O, the boxes 1) I),having shoulders I m, post 0, and stud f, and the coiled spring (l,substantially as and for the purpose herein described.

In testimony whereof I aflix my signature in presence of two witnesses.

\VILLIAM F. FORD.

and desire to secure by Witnesses:

FRANCIS CLARE Bowen, A. J AMES LASKE.

